SYNTHESIS OF LEUCITE

Abstract

Leucite, a potassium alumino-silicate (KAlSi₂O₆), is a very promising material for dental applications. It was initially introduced into dental porcelain compositions to adjust the thermal expansion coefficient of the ceramic to be similar to that of  metal [1,2,11,12]. The mineral leucite was synthesized by melting the mixture of KNO₃, Al(OH)₃ and Cam Ranh sand in the fire of acetylene burner, which can increase the temperature to around 2000 – 2200⁰C. The obtained  material has the following properties:  bulk density r = 2,48g/cm³,  phase transformation temperature at 642,5⁰C,  thermal expansion coefficient in range of 30 to 642,5⁰C (of tetragonal) is 25,9.10^-6.K^-1, in range 642,5 to 946,8⁰C is 9,3.10^-6.K^-1 (of cubic).